Durability Study of Frequent Dry–Wet Cycle on Proton Exchange Membrane Fuel Cell

Durability is the key issue for the proton exchange membrane fuel cell application and its commercialization. Current research usually uses the accelerated stress test to decrease the experiment time, whereas the performance evolution—especially the internal state evolution—under real use may be different from that under the accelerated stress test. In addition, studies rarely report this kind of durability in real decay scenarios. This paper investigates the seldom-reported impact of dry–wet cycles on durability in terms of open circuit voltage (OCV), inner resistance, and hydrogen crossover current at the condition of 20,000 cycles or the equivalent 400 h, while simultaneously running the test for the same time interval in the control experiment. The mechanical and chemical test is independent. Frequent dry–wet cycles make the OCV decay over 14% compared to 6.9% under the normal decay. Meanwhile, the dry–wet cycle helps to alleviate deterioration in terms of the inner resistance decline (61% vs. 37%) and in terms of the hydrogen crossover current increase (−64% vs. 15%). The inner state evolution is irregular and against common sense. The relationship between the crack, platinum transfer, and the moisture which heals the crack is the potential reason for the above-mentioned phenomena. These findings are beneficial to navigating fuel cell storage.